The use of mobile stations as a means of sending and receiving information in the form of text and graphics is constantly increasing. Textual information can be transmitted using e.g. the short message service (SMS). Certain mobile station models are also capable of receiving various logos, icons or messages containing images.
The use of the Wireless Application Protocol (WAP) is gaining ground in solutions requiring a link between portable terminals, such as mobile stations, and Internet applications, e.g. electronic mail, WWW (World Wide Web), news groups. Using the Wireless Application Protocol, it is possible to transmit visual information as well. The Wireless Application Protocol provides an architecture which adapts mobile telephones, browsers used in mobile telephones and the WWW into a functional entity. The HTML (Hyper Text Mark-up Language) used in the WWW is converted into WML (Wireless Mark-up Language), which is a version developed for a wireless environment, when information is to be transmitted to mobile stations. At present, the description language of the WAP standard is the WML language, but the language may also be understood to be any other description language consistent with the future WAP standard. The Wireless Application Protocol consists of the following five layers: Wireless Application Environment (WAE), Wireless Session Layer (WSL), Wireless Transaction Layer (WTP), Wireless Transport Layer Security (WTLS) and Wireless Datagram Layer (WDP). ‘Wireless application environment’ refers e.g. to a WTA (Wireless Telephone Application) or to some other appropriate environment. As the lowest layer there is additionally a system-dependent layer which determines the method of conveying information within the system in question. The specifications relating to the Wireless Application Protocol are available at the WWW address www.wapforum.org.
To expand the sphere of application of present-day mobile stations so as to allow even the transmission of information requiring verification, such as various types of admission tickets or cash vouchers or equivalent, many kinds of solutions have been proposed. According to one method, the solution is to transmit the information into a mobile station by utilizing the short message function. Instead of visual verification, the verification can also be accomplished by utilizing e.g. the infrared link of the mobile station or a separate ticket printer, by means of which the user himself prints out the actual ticket to be used, observing instructions received via the Internet or in connection with an order placed via the mobile station.
A problem with a verification procedure implemented using the short message function is that the user is required to perform certain actions to present the information to be verified in connection with the verification procedure. A further problem is that, if only visual verification of the information is desired, it is not possible to add to a normal text message any property or check element of a visual nature. Such visual components include e.g. various images or patterns.
A problem with the use of an infrared link or a ticket printer is that, in order to be able to use a ticket already ordered and possibly paid for, the user has to perform complicated and time-consuming additional operations with his mobile station.
In addition, in both of the two alternative solutions described above, the user has to transfer the ticket information by some means from the mobile station to an external device in order to obtain from the device an actual ticket showing e.g. a seat number or other essential information. A separate device as described above is necessary because otherwise the text message or business card containing the ticket can be easily forged and/or copied for several people.